Electrolytic cell



Sept. 19, 1950 c. E. BOWEN ELECTROLYTIC CELL 2 Sheets-Sheet 2 Filed Nov. .19, 1946 w 22 dwr rmwwm M Z 7 a w Patented Sept. 19, 1950 ELECTROLYTIC CELL Charles Edward Bowen,

England, assignor to International Electrolytic Plant Company Limited, Sandycroft, Chester,

England Sandycroft, Chester,

Application November 19, 1946, Serial No. 710,789 In Great Britain November 24, 1945 Claims. (01. 204-256) This invention relates to improvements in electrolytic cells and more particularly to electrolytic cells for the production of oxygen and hy drogen by the electrolysis of Water of the type in which a number of cell frames are assembled together to form a unitary structure.

In such cells the gases passing out of the cells take with them entrained electrolyte which is subsequently separated from the gases in external separating means and returned to the cells.

One of the objects of the invention is to provide an improved construction of cell which allows the electrolyte to be efliciently separated from the gases immediately on their evolution so that external separating means are unnecessary. Other objects are to permit free circulation of the electrolyte without imposing strain on the diaphragms by localised pressures, and to obtain effective balancing between adjacent cells.

According to the invention an electrolytic cell is built up from a number of parallel skeleton frames, the members of each frame being of I or equivalent cross-section so that when the frames are assembled together compartments surrounding the cells proper are formed between the webs and flanges of the frames.

Each frame may be cast as a unit in metal or moulded from a suitable plastic material or it may be built up from members of the required cross-section.

An inwardly extending lip or ledge is conveniently formed integral with or secured to the inner flange of the frame to carry the diaphragm, and in cells for the production of oxygen and hydrogen this lip or ledge and the web of the frame section are offset to provide a greater space on the catholyte side of the diaphragm than on the anolyte side. The reason for this is that the hydrogen is evolved at twice the rate of the oxygen and entrains more than twice as much electrolyte, and the allocation of greater space for the catholyte eliminates local areas of high pressure on the diaphragm.

The joints between adjacent frames are of the full depth or width of the frame members so that there is a separate compartment extending all round the frame on each side of the web thereof, the compartment being defined by the web and flanges of the frame and the jointing.

Partitions are arranged at the junctions of the vertical side sections of the compartment with the bottom to isolate the bottom section from the rest.

Electrolyte is fed into the cell from the bottom section of each compartment through openings in the upper flanges of the bottom frame member, and similar openings are provided in the bottom flange of the upper frame member through which gases from the chambers on opposite sides of the diaphragm together with any entrained electrolyte pass freely upwards into the top sections of the compartments on opposite sides of the web of the frame member. In these top sections the gas and electrolyte separate and the electrolyte flows along into the side sections while the gases on opposite sides of the web pass into separate outlets mounted ontop of the frame and communicating by way of inclined passage in the frame members with the respective top sections.

One practical construction of cell in accordance with the invention for the electrolytic production of oxygen and hydrogen is illustrated by way of example in the accompanying drawings in which Figure 1 is an end elevation of one cell frame.

Figure 2 is a plan of the frame.

Figure 3 is a side elevation in part section on a larger scale of a frame.

Figure 4 is a similar elevation in part section of a frame from the other side.

Figure 5 is a side elevation in part section of three-frames assembled together.

Each frame of the cell unit illustrated is of I or H cross-section with a web It and flanges ll, I2. The frame may be cast as'a unit in metal or moulded from a suitable plastic material, or it may be built up from members of the required cross-section. The web H] is offset from the central plane of the frame. On the inner flange of the frame there is an inwardly extending lip or ledge l3 which may be integral with or may be secured to the flange and which carries the diaphragm l4, this lip being offset to the same extent as the web Iii.

When a number of frames are assembled together as shown in Figure 5 with the electrode plates l5 and a wide strip of jointing material 16 lying between the frames and of the full width of the frame members over the flanges there are formed on opposite sides of the web of each frame separate compartments ll, i8 extending completely around the cell. I

Each of these compartments is defined by the web and flanges of the frame member and the jointing I6 which constitutes a partition between the adjacent compartments of adjacent frames.

The bottom section is of each compartment is isolated from the slide sections by horizontal partitions 20.

Electrolyte is fed into the bottom section I! of each compartment and flows upwardly into the cell through openings 2| in the upper flanges l l of the bottom frame member. Gases generated in the cell on opposite sides of the diaphragm, together withrany entrained electrolyte, pass upwardly through openings 22 in thelower flanges of the top frame member into the separate sections Il, I8 on opposite sides of the web.

is obtained, and that uniformity of electrolyte outflow from each cell is obtained by the control of the liquid level in the side sections of the com partments which prevents any disturbance of working conditions through current variations.

The duplication of theelectrolyte circulating system largely eliminatesinequalities in electrolyte concentration in individual cells, and the arrangement for handling the electrolyte circu- In these sections the gas and electrolyte separate o lation in insulated ducts of relatively small and the electrolyte flows along into the sidesections of the compartments. \Gasfrom-the-sefction I! on one side of the :web flowsathroughan inclined passage 23 in the=upper flange iofrthe frame member into an outlet 24 on the top of the frame while gas from theother section .I.8 flows through an oppositely inclined passage 25 to an outlet 26.

To allow movement of electrolyte between aidjacent compartments openings 21 are provided in the web of the bottom .frame member :and small ports .28 are provided in the web .separating the side sections adjacent to the partitions .20. Mixing ofthe gases is prevented by an externally made seal which maintains aicertain rminimum depth-of electrolyte in the-side sections .of the compartments.

.For the feeding of the electrolyte a pad or zgasketfill isprovided at thebotto-m of the frame goneeach side to receive a block 3! of insulating material whichis bored horizontally-to form two vertically spacedducts 32, 33 having their axes vat right anglesto the plane of the frame. The npperqduct :32 .is in communication through a horizontal passage 34 with .the side section of the adjacent compartment above the partition 20 and the lower ,duct 33 is .in communication "through a a passage ,3 5 (with-the bottom section .I 9.

When aenumberof frames are :assembled to gether as shown in Figure 5 packing washers '36 are arranged between the adjacent: endsof .the ducts in adj acentblocks -which;provide ,twocon- .tinuous ;ducts extending along each side .of the unit, the upper duct receiving theoverflowelec- :trolyte from the side zsections ,of the compartments and the lower ducttaking the ,returnflow of electrolyteto thecells.

The overflow electrolyte. can betaken off atany convenient point througha vesselhavingrmeans for correcting the temperature of .the .electrolyte which .is .fed back to the cells either direct or through a. circulating pump.

With a direct .feed the .side sections .of. the compartments are flooded with electrolyte and the circulation is caused by the difference in specific gravity between the electrolyte .in the side sections of the compartments and the -.mix- .ture of gas .and electrolyte inthe cell and also by the-slight difference in temperature.

If a circulating pump is used the amount of electrolytein the side sections of thecom part- .ments :can be -;reduced by transference of the electrolyte to a balance tank and the ;,rate 'of circulation of the electrolyte through the cells can .be greatly :increased, thus permitting .an increased current :rating. As the .reduction "of -:the amount of overflow le aves. more 1 space: available the efficiency of the separationof the :elec- ,trolyte :from the gases is maintained at the .higher rating.

The improved cell has annumber of advantages .inpraotice over existing cells-amongst whichrare .that efficient'separation of the electrolyte from ithe gases is effected 2.5150011 .as the ,gasesga-re evolved, that effective balancing between-thecells cross-section minimises stray current losses.

claim: 1

-1..An electrolytic cell comprising a plurality iofiskeletonframeszassembled together in parallel relationship to form a unitary structure, each membenof each .ofsaid frames being of I-section iformedibyspaced flanges and a connecting web, the webs of all the members in each frame being in the same plane, jointing material between the members of adjacent frames co-operating with the edges :of -therflanges :and constituting ,pa-rtitionsso as to;.f01m "with theweb and-flaneescof each frame closed gcompartments ,having top, side and :bottom :sections surrounding-acell'snace, and "other partitions between theibottom section and the side sectionsof each of said compartments, .each frame rloeing provided with ports of communication between :the top and bott0m s ections of said compartments and said cell :space. with discharge ports from :the to-psections and from-the lower parts .of the side sections ofssaid compartments, and -with :at least one inlet port :to ".theIbOttOlTl :sectionsof .tsaid compartments.

2. An electrolytic cell as claimed :in .claimv 11, wherein ;-said,:.jointing :material is in .sheet form.

.3. .An electrolytic cell :as claimed in -c1aim-I1, each of said .members'including a lip extending inwardly from the inner flange z-thereof, -,and:;-a

diaphragm carried by :the ..1ips: of .the emembers :Qf each-frame.

.4. .An electrolytic cell ;as claimed in claim :1, each of .said members. including a ;lip -sextending inwardlyrfrom the inner flange thereof saidaweb and said .lip being offset from :the central plane .of the frame, and adiaphragm.carried.by the lips of the members 20f :each ;frame, ,-wher.eby the compartment on .the one .side of the web :ofreach frame is of greater volume than that :on ;the other aside and the cell spaceson the cor-- responding side of the diaphragm,is;,of,;greater volume thanthat onthe otherside.

..5.,An electrolytic cellcomprising a plurality ofskeleton frames assembled togetherin gparallel relationship to form a unitary structure, each .memberof ,each of said frames being oil-section formed by :spaced flanges and a connecting web, the .webs of all the members ineachrframebeing .in the vsame plane, 'gjointing -material between .the -members of adjacent frames co-operating .with .the edges of the flanges and constituting partitions so as to form with .the web :and flanges .of :each :frame closed ecompartments surrounding a cell space, other partitionsat the junction of the side sections of 1eachccompartmentflwith .the bottom section t0,18018116"thG'bOttOmSQCUiOIl, each framebeing providedwith openingsjn the upper .iflanges .of the bottom frame :memher through which electrolyte passes :from ,thezbottomrsection,intothe.-,cell space, means for-withdrawing ;electrolyte :from the side sections, and ,means for introducing electrolyte :to the bottom (sections. 7 v

6. An electrolytic cell as claimed in claim '35 wherein each frame is further rprovided'awith .ilorts :in the :Web aof. :the frame member i-separat ing the side sections of adjacent compartments, said ports being above and close to the partitions at the junctions of the side sections with the bottom sections.

7. An electrolytic cell comprising a plurality of skeleton frames assembled together in parallel relationship to form a unitary structure, each member of each of said frames being of I-section formed by spaced flanges and a connecting web, the webs of all the members in each frame being in the same plane, jointing material between the members of adjacent frames and constituting partitions so as to form with the web and flanges of each frame closed compartments having top, side and bottom sections surrounding a cell space, a diaphragm secured to each frame in said cell space substantially in the plane of said webs, and other partitions between the bottom section and the side sections of each compartment, each frame being provided with first ports in the inner flange of its top member on opposite sides of the web to allow gases from the cell spaces on opposite sides of the diaphragm together with any entrained electrolyte to pass into the upper sections of the compartments on opposite sides of the web, second ports in the outer flange of the top member through which the gases may be taken off while electrolyte separated from the gases drains down into the side sections of the compartments, means for draining off electrolyte, and means for feeding electrolyte into the bottom sections.

8. An electrolytic cell comprising a plurality of skeleton frames assembled together in parallel relationship to form a unitary structure, each member of each of said frames being of I-section formed by spaced flanges and a connecting web, the webs of all the members in each frame being in the same plane, jointing material between the members of adjacent frames cooperating with the edges of the flanges and constituting partitions so as to form with the web and flanges of each frame closed compartments surrounding a cell space, other partitions at the junction of the side sections of each compartment with the bottom section to isolate the bottom section, each frame being provided with openings in the upper flanges of the bottom frame member through which electrolyte passes from the bottom sections into the cell space, a

gasket at the bottom of each frame on each side, a block of insulating material secured to each gasket, each block being provided with two vertically spaced horizontal ducts having their axes at right angles to the frame, said gaskets and the adjacent side members being provided with passages establishing communication between the upper ducts of the associated blocks and the side sections of the adjacent compartments and between the lower ducts and the bottom sections, said blocks, combining in said unitary structure of frames to provide tWo combined ducts extending along said structure on each side, the upper combined duct receiving the overflow electrolyte from the side sections, and the lower combined duct taking the return flow of electrolyte to the cells.

9. A frame of an electrolytic cell unit comprising a rectangular structure formed of top, side and bottom members, each of said members being of I-section formed by spaced inner and outer flanges and a, connecting web, the webs of all the members being in the same plane, partitions across the flanges of the side members substantially at their junction with the bottom member so as to form on each side of said plane one bottom channel closed at its ends, and another continuous channel extending along the remaining sides of said rectangle, and each member having on its inner flange an inwardly extending lip for carrying a diaphragm.

10. A frame as claimed in claim 9, said webs and said lips being offset to one side of the central plane of the frame.

CHARLES EDWARD BOWEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,181,549 Shriver May 2, 1916 1,344,220 Benjamin June 22, 1920 1,372,442 Levin Mar. 22, 1921 1,420,037 Harris June 20, 1922 1,855,732 Smith Apr. 26, 1932 2,446,692 Collins Aug. 10, 1948 2,450,723 Elrad 1 Oct. 5, 1948 

1. AN ELECTROLYTIC CELL COMPRISING A PLURALITY OF SKELETON FRAMES ASSEMBLED TOGETHER IN PARALLEL RELATIONSHIP TO FORM A UNITARY STRUCTURE, EACH MEMBER OF EACH OF SAID FRAMES BEING OF I-SECTION FORMED BY SPACED FLANGES AND A CONNECTING WEB, THE WEBS OF ALL THE MEMBERS IN EACH FRAME BEING IN THE SAME PLANE, JOINTING MATERIAL BETWEEN THE MEMBERS OF ADJACENT FRAMES CO-OPERATING WITH THE EDGES OF THE FLANGES AND CONSTITUTING PARTITIONS SO AS TO FORM WITH THE WEB AND FLANGES OF EACH FRAME CLOSED COMPARTMENTS HAVING TOP, SIDE AND BOTTOM SECTIONS SURROUNDING A CELL SPACE, AND OTHER PARTITIONS BETWEEN THE BOTTOM SECTION AND THE SIDE SECTIONS OF EACH OF SAID COMPARTMENTS, EACH FRAME BEING PROVIDED WITH PORTS OF COMMUNICATION BETWEEN THE TOP AND BOTTOM SECTIONS OF SAID COMPARTMENTS AND SAID CELL SPACE, WITH DISCHARGE PORTS FROM THE TOP SECTIONS AND FROM THE LOWER PARTS OF THE SIDE SECTIONS OF SAID COMPARTMENTS, AND WITH AT LEAST ONE INLET PORT TO THE BOTTOM SECTIONS OF SAID COMPARTMENTS. 